Slide fastener with plastic coupling elements



H. POREPP 3,399,436

SLIDE FASTENER WITH PLASTIC COUPLING ELEMENTS Sept. 3, 1968 Filed Nov. 14, 1966 INVENTOR Hans Porepp Attorney United States Patent 4 Claims. (Cl: 24-20543 ABSTRACT OF THE DISCLOSURE A slide fastener stringer whose halves each comprise a support or carrier tape or ribbon along the approaching longitudinal edges of which are provided coupling elements consisting of continuous meanders of flattened figure-eight profile with a longitudinal axis between the two sets of bends or bights formingeach meander, the meanders being stitched to the respective tapes by two rows of stitches on opposite sides of this axis and passing through the vertices of the acute angles formed between the pairs of legs of the meanders, thereby preventing shifting of the coupling elements in their planes transversely to the longitudinal direction.

This invention relates to a slide-fastener stringer comprising two coupling elements or rows of coupling heads, each made of a plastic (synthetic-resin) thread in the form of a meander and secured to a carrier ribbon.

Rows of coupling links for slide fasteners have hitherto been manufactured such that a synthetic-resin thread is deposited to and fro in one plane in a meandering fashion, whereupon the meander is provided with coupling surfaces or heads by coining the strand along the longitudinal centerline and bending it into a U-profile, the legs of which straddle the edge of a carrier ribbon or tape and are secured thereto by a sewing seam. A cover strip may simultaneously be sewn to the side of the row of coupling links which face away from the carrier ribbon. In these meander slide fasteners the legs of the U-shaped meander are disposed substantially normally (perpendicularly) to the longitudinal direction of the slide fastener, whereby these legs can move in the stitch loops in their longitudinal direction relative to the carrier ribbon. In a similar manner this movement is also possible if the syntheticresin thread of a row of coupling links is wound in a helical coil except where special means are provided, such as filler cores and the like.

This movement of the coupling elements in the rows of coupling links may be the reason why the slide fastener halves with their coupling surfaces do not lie linearly and why the movement of the coupling slide for securing the slide-fastener halves is impeded, if not even jammed. The possibility of shifting of the meander or helical members in their plane normally to the longitudinal direction of the slide fastener may be avoided by providing a plurality of parallel seams, for example by double-chain-stitch seams, but the attachment of coupling elements by a plurality of seams is very difficult, since the interspaces between the individual heads or links through which two or more needles must pass, are very narrow.

The object of this invention is to prevent, in a simple manner, any transverse movement of continuous rows of coupling links relatively to the carrier ribbon and transversely to the longitudinal direction of the slide fastener, and to facilitate the attachment of the coupling element by a plurality of seams.

The invention solves the problem by providing that each row of the coupling links is deposited in the form of a recumbent figure eight so as to form a meander the 3,399,436 Patented Sept. 3, 1968 return bends or bights of which lie in planes normal to the longitudinal direction and are provided with coupling surfaces, and is attached by parallel seams to a carrier ribbon; the stitches of the seams being disposed on either side of the longitudinal center line of the meander between the return bends.

Due to this shape of the planar meander and to the arrangement of the sewing stitches at either side of the longitudinal centerline between the return bends on either side, the meander cannot move in its plane relative to the carrier ribbon, normally to the longitudinal direction of the slide fastener, whereby the movement of the slide is no longer impaired; also it makes no difference whether the return bends of the one or the other side of the meander form the coupling surfaces at which the coupling elements engage.

In addition, it will be appreciated that the height of the slide fastener above the carrier ribbon is very small and that the coined coupling surfaces facing away from the coupling surfaces used for coupling forming an almost continuous edge for guiding the slide. In any case; thus construction provides suflicient room for the stitches and the sewing needles of the individual seams.

The invention shall now be described in detail in connection with an embodiment thereof shown in the drawing, in which:

FIG. 1 is a top view of a row of slide-fastener coupling links according to the invention attached to carrier ribbon by sewing; and

FIG. 2 is a cross-sectional view of two coupled slidefastener halves according to FIG. 1.

In the embodiment of the drawing, a plastic thread 1 is used to form a row of coupling links in the form of a meander, in such a manner that the return bends or bights of the meander, which are provided with corresponding surfaces 2, are disposed in planes perpendicular to the longitudinal direction of the meander with legs of the bend superposed in contacting engagement, the meander having the profile of a lying eight. There is no difliculty in producing this form of the meander, as mentioned in another, co-pending application.

Now, according to the invention, this flat meander is sewed to a carrier ribbon by using a double seam 4, 5 in such a manner that the sewing stitches of the two seams each are disposed on opposite sides of the longitudinal center line of the meander between the return bends or bights of each meander link, these bends being provided with the coupling surfaces 2. In this arrangement, a sufliciently large gap is formed between the return bends on either side, and thus the sewing stitches, or the sewing stitches of both seams respectively, extending through the carrier ribbon, are supported practically in a vertex of the angle formed by the meander legs, whereby lateral shifting of the row of meander elements normally to the longitudinal direction of the meander and relative to the carrier ribbon 3 becomes impossible. The double seam 4, 5 may also be a double chain stitch seam with the underthreads 4a and 5a disposed on that side of the row of coupling links which is facing away from the carrier ribbon 3, thereby forming an ironing protection. But it is also possible to proceed such that, together with the row of coupling links, a narrow cover strip is sewed to the carrier ribbon 3, and instead of the narrow strip also a string, or the like, may be used. Finally it is also possible to sew the covering strip or string together with the row of coupling links by two chain-stitch seams 4, 5 to the carrier ribbon, in which case the underthreads of the chain stitch seams are disposed on the side of the carrier ribbon opposite the rows of coupling links. If this occasion arises it is also possible to use a zigzag seam for attaching the row of coupling links to the carrier ribbon, the stitches of which. are disposed alternately between the return bends on both sides of row of coupling links; and also in this case an ironing protection in form of a narrow strip or string, may be secured simultaneously by the zigzag seam.

What I claim is:

1. In a slide fastener comprising two continuous coupling elements forming respective links each made of a plastic thread shaped in form of a meander and secured to a carrier ribbon, the improvement wherein each row is generally fiat with the coupling links having the form of a recumbent figure eight so as to form a meander, the return bends of which lie in planes normal to the longitudinal dimension of the rows and are provided with coupling surfaces, and each coupling element is attached by parallel seams to a respective carrier ribbon, the sewing stitches of the seams being disposed on either side of the longitudinal centerline of the respective row between its return bends.

2. The improvement defined in claim 1 wherein the parallel seams each are formed as a double-chain-stitch seam, the underthreads of which lie on the side of the respective row of coupling links which faces away from said carrier ribbon.

3. The improvement defined in claim 1 wherein a respective narrow strip is disposed on the side of each row of coupling links facing away from said carrier ribbon, said narrow strip being stitched to said carrier ribbon by stitches traversing the respective row between the return bends thereof.

4. The improvement defined in claim 3 wherein said strip together with the respective row of coupling links is sewed to its carrier ribbon by two chain-stitch seams, the underthreads of which are disposed on that side of the row of coupling links which faces away from said carrier ribbon.

References Cited UNITED STATES PATENTS 1,581,751 4/1926 Marinsky. 2,919,482 1/1960 Casson. 3,149,388 9/1964 Wilken 24--2O5.l

BERNARD A. GELAK, Primary Examiner. 

